<header id="header">
    <a href="/" id="logo"></a>

    
    <nav id="nav">
        <!-- <a href="">- {{title}} -</a> -->

        {% for category in categories %}
        <a href="">{{category.name}}</a>
        {% endfor %}
    </nav>

    <div id="user">
        <a href="/register">注册</a>
        <a href="/login">登录</a>

        <a href="/additem">添加商品</a>
    </div>
</header>